There is presently no line of distinction between oral lichen planus and other oral lichenoid lesions. The aim of this study is to determine using histomorphometry, the differences between these lesions. Paraffin sections from 7 normal buccal epithelium, 19 oral lichen planus (LP), 14 oral lichenoid lesions (LL) and 7 discoid lupus erythematosus-like lesions (DLE-II) were selected. The nuclear volume (VN) and cellular-volume (VCELL) of the epithelium were assessed using an image analyser. The VN and VCELL derived for both basal and spinal strata in LP and DLE-II were 2.3 times more than that of normal tissues. There was a significant difference between LP and LL (P<0.005) and between LL and DLE-II (P<0.001), but not between LP and DLE-II. In conclusion, there appears to be a difference between LP, LL and DLE-II and VN and VCELL may serve as potential discriminators between these groups of lesions. (J. Oral Sci. 43, 151-157, 2001)

Porphyromonas gingivalis is a gramnegative anaerobic bacterial species implicated as an important pathogen in the development of adult periodontitis. Hemagglutinin may mediate the adsorption and invasion of bacteria into host cells. Furthermore, the hemagglutinin plays a role in the agglutinate and lyse erythrocytes intake of heme which is an absolute requirement for this bacterial growth. We previously cloned the gene encoding the130-kDa hemagglutinin protein domain (130-kDa HMGD) and identified the functional motifs of agglutination of erythrocytes. Bacterial cell attachment to erythrocytes is an important initial step in the expression of hemolytic activity. In this study, we highly purified recombinant r130-kDa HMGD and prepared the specific antiserum. Further, the effect of the antibody on the hemolytic activity of P. gingivalis cells was examined. The polyclonal antibody recognized 43, 49-kDa major bands in P. gingivalis cells and r130-kDa HMGD, and significantly inhibited the hemagglutinating and hemolytic activities of P. gingivalis cells. The findings suggest that the antibody may be useful in the development of the passive immunization against periodontal diseases caused by P. gingivalis infection. (J. Oral Sci. 43, 159-163, 2001)

Papillary squamous cell carcinoma (PSCC) is a poorly described variant of squamous cell carcinoma, and may be confused with verrucous carcinoma of the head and neck. To add to existing knowledge of this rare tumor, we describe two cases of PSCC arising in the oral mucosa. The lesions were composed of exophytic proliferation of atypical to overtly malignant cells similar to those of conventional squamous cell carcinoma, and invasion into the superficial region of the underlying fibrous tissue was seen in the form of islands and cords of malignant cells. Immunohistochemical assessment of cellular proliferative activity showed a significantly high mean percentage of Ki-67 expression in comparison with verrucous carcinoma, but there was no significant difference of Ki-67 expression among PSCC, conventional squamous cell carcinoma and microinvasive squamous cell carcinoma. These results suggest that the biological behavior of PSCC is analogous to that of SCC. (J. Oral Sci. 43, 165-169, 2001)

Interleukin-1 beta (IL-1β) is a potent bone-resorptive cytokine that also mediates soft-tissue destruction by stimulating prostaglandin production and inducing collagenase and other protease activity. The literature suggests that this substance may be an important mediator of attachment loss in human periodontitis, and indicates that IL-1β may be useful for locating sites of periodontal disease activity. There is some evidence that IL-1β is produced by cells of the periodontium, and that it can be detected in gingival crevicular fluid (GCF). Many factors are known to contribute to the destruction of periodontal tissue. One of the most important is immune deficiency in diabetes. The aim of this study was to measure and compare the concentration of IL-1β in the GCF of patients with noninsulin-dependent diabetes mellitus (Type 2 DM), otherwise healthy adults with periodontitis, and individuals with no periodontal disease in order to assess whether diabetes alters IL-1β levels. We also examined relationships between GCF levels and the clinical parameters of pocket depth, plaque index, and bleeding index in each group. Seventeen patients with Type 2 DM, 17 adult periodontitis patients (AP), and 17 healthy controls were selected. The levels of IL-1β in the GCF were quantified by ELISA. The mean IL-1β concentrations in the Type 2 DM, AP, and control groups were 200.1±65.34 pg/μl, 131.35 ± 67.66 pg/μl, and 80.0 ± 36.08 pg/μl, respectively. The levels in the diabetic patients were significantly higher than those in the AP and control subjects. There were no significant correlations between IL-1β level and any of the clinical data parameters for each group. We believe that the macrophages may over produce IL-β in Type 2 DM and increased IL-1β levels in diabetic patients could be linked to altered immune function. (J. Oral Sci. 43, 171-177, 2001)

We investigated the expression of the small proteoglycans, decorin and biglycan, which are associated with osteoblast differentiation, and how this relates to the expression of osteocalcin and bone sialoprotein (BSP) early in the formation of bone in the rat mandible by immunohistochemistry and in situ hybridization. The mandibles of rat fetuses were collected on embryonic days 14 (E14) to E18. In situ hybridization showed that gene expression of decorin, biglycan, osteocalcin and BSP was not apparent in the developing mandible at E 14, but was expressed by newly differentiated osteoblasts at E15. The expression of these mRNAs increased linearly as the number of osteoblasts increased in specimens from E16 to E18. Immunohistochemistry showed that newly differentiated osteoblasts expressed biglycan moderately, decorin weakly, and osteocalcin and BSP faintly. The unmineralized bone matrices among the osteoblasts showed prominent staining for decorin, weak staining for osteocalcin and BSP, and very weak staining for biglycan. When the intercellular matrix was mineralized at E16, the mineralized bone matrix showed more prominent staining for osteocalcin and BSP, but lacked staining for decorin and biglycan. The same staining profile was observed during the subsequent phases of bone formation at E17 and E18. These results indicate that decorin, biglycan, osteocalcin and BSP are expressed at the gene and protein level by newlydifferentiated osteoblasts before the onset of matrix mineralization and that they could play a role in the earliest stages of bone formation. Negative proteoglycan staining in the mineralized bone matrix suggests that a loss of, or a sharp decrease in proteoglycans occurs concomitant with bone matrix mineralization. (J. Oral Sci. 43, 179-188, 2001)

Since the development and use of the high-speed dental air turbine some 45 years ago, concern has been expressed in the literature about a possible cause and effect relationship between use of the drill and hearing loss in dentists. The hearing threshold in humans varies with the frequency of sound. It is well known that dentists experience gradual hearing loss during their working life. The aim of this study was to measure the frequency of sounds emitted by highspeed dental air turbines under different working conditions. Five high-speed dental air turbines were used (2×Trend TC-80 BC W&H Dentalwerk, Austria, 2×Black Pearl Eco Bien-air, Switzerland, 1×Trend TC-80 BC W&H Dentalwerk, Austria. Each turbine was tested under 8 different working conditions : under free working conditions the turbines were tested without burs, with fissure burs, with flare burs, with round burs and with inverted cone burs; under operation they were tested with fissure burs by application to a 3×3×10 mm amalgam block surface, a 3×3×10 mm composite block surface, and the occlusal surface of an extracted molar tooth. Forty sound recordings were made in total using a computer with a microphone (Shure 16 LC) located 30 cm away from the samples, at 10-s intervals using a mixer. Frequency analysis was done by a Cool Edit Pro 1.2 computer program. Data were analyzed by multi-variate analysis with the S.P.S.S 9.05 software program. The average measurement was 6860 Hz. According to the statistical analysis there was no significant difference in the frequencies recorded under different working conditions. There was also no significant difference among the different highspeed dental air turbines at α=0, 05, P>α/2 levels. These results indicate that under any working conditions, high-speed dental air turbines emit frequencies which can cause hearing loss. (J. Oral Sci. 43, 189-192, 2001)

The aim of this in vitro study was to compare the color stability of commercially available porcelain, reinforced acrylic, and conventional acrylic denture teeth materials used in removable prostheses. Two brands of porcelain (Unilux-Enta Lactona-Holland and Vivoperl-Ivoclar-Liechtenstein), 2 brands of reinforced acrylic (Optodent-Bayer-Germany and Ivolek-Ivoclar-Liechtenstein), and 2 brands of conventional acrylic (Isodent-Güney Dis Deposu-Turkey and Samed-Turkey), were made, for a total of 6 different denture teeth groups. Denture teeth were subjected to 3 staining solutions (filtered coffee, tea, and cola) and distilled water. From each group of denture teeth, 4 sets of maxillary anterior denture teeth were immersed in each of the 4 solutions. The color values of denture teeth were measured colorimetrically with the Gardner XL 20 Tristimulus Colorimeter (Gardner Lab. Inc., Bethesda, Maryland, USA). Color changes were characterized in the CIEL*a*b* color space. Color change values were determined after 1 day, 1 week, 2 weeks, and 4 weeks. The color difference values were calculated and then evaluated by two-way ANOVA statistically. The filtered coffee solution was found to be more chromogenic than the other 2 staining solutions, while porcelain denture teeth materials were more color stable. Assuming the color change of ΔE*<1.0 as a discernible limit and ΔE*=3.3 as an acceptable value, the filtered coffee, tea, and cola had slight staining effects on all 6 groups of denture teeth. (J. Oral Sci. 43, 193-205, 2001)

Individuals with Down syndrome (DS) have a high prevalence of periodontal disease, which develops early and progressed rapidly and extensively, in comparison with healthy controls. The severe periodontal disease in individuals with DS has been considered to result from abnormal factors in their host responses. The mechanisms involved in the periodontal inflammatory processes in individuals with DS are not fully understood. Plasminogen activators (PA) are serine proteases that are well known for their part in the initiation of the fibrinolytic cascade leading to the generation of plasmin in periodontal homeostasis, including fibrinolysis and connective tissue remodeling. The PA-plasmin system affects the progression of periodontal disease. In the present study, we examined the effects of the levels of PA activity stimulated with lipopolysaccharide (LPS) in the gingival fibroblasts from donors with DS (DGF). The levels of PA activity without LPS were low in the DGFs, the same as that in the gingival fibroblasts from donors of healthy controls (NDGF). In contrast, the levels of PA activity with LPS in DGFs were significantly higher than that in the NDGFs. These results suggested that PA plays an important role in inducing extensive and rapid inflammation in the periodontal disease in individuals with DS. (J. Oral Sci. 43, 207-212, 2001)

The discoloration of tooth roots is rare. We report here a 22-year-old Japanese woman with blackish-brown staining of the roots of the upper and lower third molars. Staining was found in the dentin and cementum. Electron probe X-ray microanalysis showed no significant difference in the composing elements between the stained tooth root and control tooth. Fluorescent bands coincided with staining in the dentin of the root and cementum along the incremental lines under confocal laser-scanning microscope. (J. Oral Sci. 43, 213-215, 2001)

Nodular fasciitis of the cheek is an extremely rare lesion of the oral cavity. It should be considered in the differential diagnosis of swellings in the oral mucosa. We describe a case of nodular fasciitis and discuss the difficulties of histological and clinical diagnosis of this condition. (J. Oral Sci. 43, 217-220, 2001)

Alstrom syndrome is a rare disorder characterized by early obesity, loss of central vision, diabetes mellitus, hearing loss and short stature. Previous studies, have reported no information regarding oral findings. This article describes oral findings in two cases of Alstrom syndrome. In both cases, gingivitis was present and also light yellowbrown discolored enamel bands were observed on the anterior teeth. This staining may have resulted from discoloration of the preexisting slight band-like enamel hypoplasia. The gingiva was examined histologically by light and transmission electron microscopy. Irregular thickness of the basal lamina and delamination of the myelin sheath were detected by transmission electron microscopy. There is no information about pathological odontogenesis in Alstrom syndrome in previous reports. Oral present findings may contribute further information about the clinical manifestations of Alstrom syndrome. (J. Oral Sci. 43, 221-224, 2001)